scholarly journals Bacterial community structure along the Adour estuary (French Atlantic coast): influence of salinity gradient versus metal contamination

2007 ◽  
Vol 49 ◽  
pp. 47-56 ◽  
Author(s):  
MS Goñi-Urriza ◽  
D Point ◽  
D Amouroux ◽  
R Guyoneaud ◽  
OFX Donard ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Metal Contamination ◽  
Bacterial Community Structure ◽  
Salinity Gradient ◽  
Atlantic Coast

scholarly journals Influence of hydrological factors on bacterial community structure in a tropical monsoonal estuary in India

2021 ◽  
Author(s):  
Parvathi Ammini ◽  
Michela R Catena ◽  
Jasna Vijayan ◽  
Nikhil Phadke ◽  
Nikhita Gogate
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Bacterial Communities ◽  
Bacterial Community Structure ◽  
Salinity Gradient ◽  
Pearson Correlation ◽  
Temporal Variations ◽  
Spatial And Temporal Variation ◽  
Physico Chemical ◽  
The Impact

Abstract In the present study, we analysed variations in bacterial community structure along a salinity gradient in a tropical monsoonal estuary (Cochin estuary, CE), on the southwest coast of India, using Illumina next-generation sequencing (NGS). Water samples were collected from eight different locations thrice a year, to assess the variability in the bacterial community structure and to determine the physico-chemical factors influencing the bacterial diversity. Proteobacteria was the most dominant phyla in the estuary followed by Bacteroidetes, Cyanobacteria, Actinobacteria, and Firmicutes. Statistical analysis indicated significant variations in bacterial communities between freshwater, mesohaline and euryhaline regions, as well as between the monsoon (wet) and non-monsoon (dry) periods. Non-metric multidimensional scaling (NMDS) analysis demonstrated that the bacterial communities cluster according to different salinity regimes of the estuary. Canonical Correspondence analysis (CCA) showed a clear spatial and temporal variation in the distribution of bacterial communities in the CE. Abundance of Betaproteobacteria was high in the freshwater regions, while Gammaproteobacteria, Alphaproteobacteria and Epsilonproteobactera were more abundant in mesohaline and euryhaline regions of the estuary. Correlagram based on Pearson correlation analysis demonstrated the impact of different physico-chemical variables on the distribution of dominant phyla, class and genera. Spatial and temporal variations in bacterial community structure could be due to regional variations in environmental conditions imparted by allochthonous inputs, monsoonal rainfall, and tidal influence.

Temporally invariable bacterial community structure in the Arabian Sea oxygen minimum zone

2014 ◽  
Vol 73 (1) ◽  
pp. 51-67 ◽  
Author(s):  
A Jain ◽  
M Bandekar ◽  
J Gomes ◽  
D Shenoy ◽  
RM Meena ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Bacterial Community Structure ◽  
Arabian Sea ◽  
Oxygen Minimum Zone ◽  
Minimum Zone ◽  
Oxygen Minimum

scholarly journals The root endophytic bacterial community of Ricinus communis L. resembles the seeds community more than the rhizosphere bacteria independent of soil water content

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Stephanie E. Hereira-Pacheco ◽  
Yendi E. Navarro-Noya ◽  
Luc Dendooven
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Plant Development ◽  
Bacterial Community Structure ◽  
Ricinus Communis ◽  
Ricinus Communis L ◽  
Endophytic Bacterial Community

AbstractRhizosphere and root endophytic bacteria are crucial for plant development, but the question remains if their composition is similar and how environmental conditions, such as water content, affect their resemblance. Ricinus communis L., a highly drought resistant plant, was used to study how varying soil water content affected the bacterial community in uncultivated, non-rhizosphere and rhizosphere soil, and in its roots. Additionally, the bacterial community structure was determined in the seeds of R. communis at the onset of the experiment. Plants were cultivated in soil at three different watering regimes, i.e. 50% water holding capacity (WHC) or adjusted to 50% WHC every two weeks or every month. Reducing the soil water content strongly reduced plant and root dry biomass and plant development, but had little effect on the bacterial community structure. The bacterial community structure was affected significantly by cultivation of R. communis and showed large variations over time. After 6 months, the root endophytic bacterial community resembled that in the seeds more than in the rhizosphere. It was found that water content had only a limited effect on the bacterial community structure and the different bacterial groups, but R. communis affected the bacterial community profoundly.

scholarly journals Bacterial community structure alterations within the colorectal cancer gut microbiome

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mark Loftus ◽  
Sayf Al-Deen Hassouneh ◽  
Shibu Yooseph
Keyword(s):  
Colorectal Cancer ◽  
Community Structure ◽  
Bacterial Community ◽  
Gut Microbiome ◽  
Late Stage ◽  
Bacterial Community Structure ◽  
Whole Genome ◽  
Human Gut ◽  
Fecal Samples ◽  
Human Gut Microbiome

Abstract Background Colorectal cancer is a leading cause of cancer-related deaths worldwide. The human gut microbiome has become an active area of research for understanding the initiation, progression, and treatment of colorectal cancer. Despite multiple studies having found significant alterations in the carriage of specific bacteria within the gut microbiome of colorectal cancer patients, no single bacterium has been unequivocally connected to all cases. Whether alterations in species carriages are the cause or outcome of cancer formation is still unclear, but what is clear is that focus should be placed on understanding changes to the bacterial community structure within the cancer-associated gut microbiome. Results By applying a novel set of analyses on 252 previously published whole-genome shotgun sequenced fecal samples from healthy and late-stage colorectal cancer subjects, we identify taxonomic, functional, and structural changes within the cancer-associated human gut microbiome. Bacterial association networks constructed from these data exhibited widespread differences in the underlying bacterial community structure between healthy and colorectal cancer associated gut microbiomes. Within the cancer-associated ecosystem, bacterial species were found to form associations with other species that are taxonomically and functionally dissimilar to themselves, as well as form modules functionally geared towards potential changes in the tumor-associated ecosystem. Bacterial community profiling of these samples revealed a significant increase in species diversity within the cancer-associated gut microbiome, and an elevated relative abundance of species classified as originating from the oral microbiome including, but not limited to, Fusobacterium nucleatum, Peptostreptococcus stomatis, Gemella morbillorum, and Parvimonas micra. Differential abundance analyses of community functional capabilities revealed an elevation in functions linked to virulence factors and peptide degradation, and a reduction in functions involved in amino-acid biosynthesis within the colorectal cancer gut microbiome. Conclusions We utilize whole-genome shotgun sequenced fecal samples provided from a large cohort of late-stage colorectal cancer and healthy subjects to identify a number of potentially important taxonomic, functional, and structural alterations occurring within the colorectal cancer associated gut microbiome. Our analyses indicate that the cancer-associated ecosystem influences bacterial partner selection in the native microbiota, and we highlight specific oral bacteria and their associations as potentially relevant towards aiding tumor progression.

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